EFFICACY OF ENDOSCOPIC SUBURETERAL POLYDIMETHYLSILOXANE INJECTION FOR TREATMENT OF VESICOURETERAL REFLUX IN CHILDREN: A NORTH AMERICAN CLINICAL REPORT

Endoscopic injection of bulking agents in pediatric vesicoureteral reflux: a narrative review of the literature

In the last 20 years, endoscopic injection (EI) has affirmed as a valid alternative to open surgery for management of pediatric vesicoureteral reflux (VUR). This study aimed to investigate and discuss some debated aspects such as indications, bulking agents and comparison, techniques of injection and comparison, predictive factors of success, use in specific situations. EI is minimally invasive, well accepted by patients and families, with short learning curve and low-morbidity profile. It provides reflux resolution rates approaching those of open reimplantation, ranging from 69 to 100%. Obviously, the success rate may be influenced by several factors. Recently, it is adopted as first-line therapy also in high grade reflux or complex anatomy such as duplex, bladder diverticula, ectopic ureters. The two most used materials for injection are Deflux and Vantris. The first is absorbable, easier to inject, has lower risk of obstruction, but can lose efficacy over time. The second is non-absorbable, more difficult to inject, has higher risk of obstruction, but it is potentially more durable. The two main techniques are STING and HIT. To date, the ideal material and technique of injection has not yet clearly established, but the choice remains dependent on surgeon's preference and experience.

Comparative Clinical Study Between Modified Ureteral Orthotopic Reimplantation and Cohen Method Under Pneumovesicum in Pediatric Patients With Hydroureteronephrosis

Purpose: To report our initial experience with a modified ureteral orthotopic reimplantation technique under pneumovesicum and compare the outcomes vs. those obtained with the Cohen technique under pneumovesicum for the correction of primary obstructive megaureter (POM) or vesicoureteral reflux(VUR) in pediatric patients. Methods: A total of 46 patients (38 POM and 8 VUR; mean age: 16.24 months) treated with modified ureteral orthotopic reimplantation (OR) and 43 patients (34 POM and 9 VUR; mean age: 22.98 months) treated with Cohen reimplantation (CR) under pneumovesicum were included. We compared the results perioperatively and during follow-up. Results: The mean operative time was significantly shorter in the OR group (OR: 86.86 and 108.18 vs. CR: 95.14 and 124.29 min for unilateral and bilateral cases, respectively). The mean postoperative hospital stay (OR: 5.02 vs. CR: 5.07 days), blood loss (OR: 3.67 vs. CR: 3.84 ml), and follow-up time (OR: 23.17 vs. CR: 23.37 months) did not exhibit significant differences between the two groups. One patient converted to open surgery in the CR group, whereas there was no conversion in the OR group. Postoperative febrile urinary tract infection occurred in two cases in each group. Both infections were controlled using antibiotics. All patients in both groups showed improved hydroureteronephrosis, and all patients with VUR showed reflux resolution post-surgery. Conclusions: Our modified ureteral orthotopic reimplantation technique under pneumovesicum can be safely and effectively performed, achieving a high success rate that is equivalent to that obtained through the Cohen technique under pneumovesicum. Moreover, it involves a simpler procedure and shorter operation time.

Significance of an endoscopically injected nodule detected on ultrasound as a predictive factor for the resolution of vesicoureteral reflux

Endoscopic treatment of vesicoureteral reflux (VUR) is feasible in pediatric patients. As endoscopic injection has a lower success rate than ureteral reimplantation, a postoperative voiding cystourethrogram (VCUG) is usually performed. The present study evaluated whether the presence of a nodule on noninvasive ultrasound could predict the resolution of VUR and replace invasive VCUG. Patients who received an injection of endoscopic bulking agent for VUR from January 2005 to December 2010 were evaluated retrospectively. It was evaluated whether a nodule, an echogenic mass lesion distinguished from the bladder at the ureteral orifice, was present on the ultrasound one month postoperatively. The success of the injection in the group with nodules was compared with that of the group without nodules by VCUG 3 months postoperatively. A total of 149 patients (220 ureters) met the inclusion criteria. The mean age at surgery was 3.5 years (range, 0.6–18 years). The overall success rate was 73.2%. A nodule was present in 152 cases (69.1%). The group with nodules had a higher success rate than the group without nodules (84.2%, 128/152 vs. 48.5%, 33/68, respectively; P<0.001). According to multivariate analysis, injection nodules were a predictive factor for the success of the endoscopic injection (odds ratio, 6.050; P<0.001). The failure rate increased with increasing injection volume. The sensitivity of sonographic injection nodules for predicting success was 79.5% and the specificity was 59.3%. To conclude, the presence of a postoperative nodule can predict the resolution of VUR.

Clinical value of persistent but downgraded vesicoureteral reflux after dextranomer/hyaluronic acid injection in children

We aimed to investigate the clinical value of persistent but downgraded vesicoureteral reflux (VUR) after dextranomer/hyaluronic acid (Dx/HA) injection in children. The medical records of 128 children (195 ureters) who underwent Dx/HA injections for VUR were reviewed. The incidences of pre- and post-operative febrile urinary tract infections (UTIs) were analyzed in children with or without persistent VUR on voiding cystourethrography (VCUG) 3 months postoperatively. The surgical results of VUR persistent children who underwent a single additional injection were assessed. The VUR resolved completely in 100 ureters (51.3%), was persistent in 95 ureters, and newly developed in 2 ureters. The incidence of pre/post-operative febrile UTIs were 0.35 ± 0.39 per year and 0.07 ± 0.32 per year in VUR resolved children (P < 0.001), and 0.76 ± 1.18 per year and 0.20 ± 0.61 per year in VUR persistent children (P < 0.001). A single additional Dx/HA injection (44 ureters) resolved VUR in 29 ureters (65.9%), and also reduced the VUR to grade I in 7 ureters (15.9%), II in 4 (9.1%), and III in 4 (9.1%). Even in children with persistent VUR after Dx/HA injection, the incidence of febrile UTIs decreased markedly. The VUR grade significantly decreases after single additional Dx/HA injection.

Endoscopic treatment of vesicoureteral reflux in pediatric patients

Endoscopic treatment is a minimally invasive treatment for managing patients with vesicoureteral reflux (VUR). Although several bulking agents have been used for endoscopic treatment, dextranomer/hyaluronic acid is the only bulking agent currently approved by the U.S. Food and Drug Administration for treating VUR. Endoscopic treatment of VUR has gained great popularity owing to several obvious benefits, including short operative time, short hospital stay, minimal invasiveness, high efficacy, low complication rate, and reduced cost. Initially, the success rates of endoscopic treatment have been lower than that of open antireflux surgery. However, because injection techniques have been developed, a recent study showed higher success rates of endoscopic treatment than open surgery in the treatment of patients with intermediate- and high-grade VUR. Despite the controversy surrounding its effectiveness, endoscopic treatment is considered a valuable treatment option and viable alternative to long-term antibiotic prophylaxis.

[Chronic limping due to calcification in a subureteric Macroplastique(®) implant]

Endoscopic subureteric implantation of polydimethylsiloxane (Macroplastique(®)) to treat vesico-ureteric reflux is known to be safe and efficient, but long-term complications of this technique are often unknown. A 15-year-old patient was admitted to several hospital services with abdominal pain in the right lower quadrant and chronic limping. After multiple examinations, the diagnosis of renal colic due to the calcification of a Macroplastique(®) implant was made. Calcification of an implant after endoscopic subureteral injection has already been described in the literature, but the clinical presentation of this complication is poorly reported, which can delay the diagnosis. The treatment can consist in an exeresis of the implanted material or even in ureteral reimplantation.

Endoscopic treatment of vesicoureteral reflux using dextranomer/hyaluronic acid copolymer in children: results of postoperative follow-up with real-time 3D sonography

OBJECTIVES

We evaluated whether real-time 3D ultrasound (4D-US) together with clinical evaluation is an alternative to voiding cystourethrography (VCUG) after endoscopic treatment of vesicoureteral reflux (VUR) in children at postoperative follow-up.

MATERIAL AND METHODS

We reviewed 178 children who underwent endoscopic therapy with dextranomer/hyaluronic acid copolymer in grade II or III VUR between 2002 and 2005. 4D-US was performed in all patients 1 day and 3, 9 and 18 months after endoscopic therapy. Only children with postoperative urinary tract infections (UTIs) and/or nonorthotopic position of the bulking agent were referred for VCUG.

RESULTS

In 93% of the ureteral units, the depot could be detected in the orthotopic position after 3, 9 and 18 months. None of these children developed UTIs in the postoperative follow-up. Twelve children demonstrated a shifting of the depot, indicating a possible therapy failure. Eight of these 12 patients (66.7%) presented a positive VCUG, and 50% of them sustained UTIs.

CONCLUSIONS

4D-US seems to be a sufficient protocol in the follow-up of children after endoscopic treatment of low-grade VUR. VCUG should be performed in cases of a shifted position of the depot; invasive investigations are unnecessary in asymptomatic children with orthotopic bulk.

[Vesico-ureteric reflux treatment by implant of polydimethylsiloxane (Macroplastique): Review of the literature]

PURPOSE

During the last 25years, endoscopic correction of vesicoureteral reflux (VUR) has become a well-recognized procedure. However, the nature of the bulking agent used has led to many controversies. The objective of this work was to perform a literature review on the use of polydimethylsiloxane (PDMS or Macroplastique) in VUR.

METHOD

A PubMed review of the literature since 1996 resulted in the selection of 24 studies of sufficient level of evidence to assess the efficacy and tolerance of Macroplastique in the VUR in adults and children.

RESULTS

The overall success rate at 1 year, 2 years and 9-years follow-up was respectively 86-93 %, 80-92 %, and 77-100 %, which confirms the maintenance of good results over time, notably in VUR grade III and above. The success rate was similar for primary and secondary VUR except for total duplicity. Predictive criterias of success were the surgeon's experience, the low grade of VUR, and the absence of previous injection. In comparison with other bulking agents, the higher viscosity and absence of shrinkage of the product increase its reliability. After more than 12years of use, no serious complication has been reported in the literature, reflecting the good tolerance of Macroplastique on the long term.

CONCLUSION

The studies published on the use of Macroplastique in VUR confirmed its efficacy, around 85 % of success for all grades, in children and adults as well. The interest of PDMS is linked to its higher viscosity promoting a better reliability and reproducibility of the technique and its non-resorbable nature providing a permanent result, especially valuable in high-grade VUR with anatomical anomaly of the vesicoureteral junction or in VUR secondary to permanent lower urinary tract dysfunction.

Endoscopic treatment of vesicoureteral reflux with polydimethylsiloxane in adults: do location and appearance of the ureteric orifice have a role in the success rates?

INTRODUCTION

Low success rate for high grade reflux and anatomical abnormality of ureteric orifices continues to be the most important dilemma of the endoscopic treatment of vesicoureteral reflux (VUR). The aim of this study was to evaluate the efficacy of endoscopic polydimethylsiloxane injection in adults with VUR concerning reflux severity and the status of the ureteric orifice.

MATERIALS AND METHODS

Fifty-three ureters (34 patients) were treated with endoscopic polydimethylsiloxane injection. The grade of VUR was I, II, III, IV and V in 2, 13, 25, 10 and 3 ureters, respectively. Any endoscopic characteristics of 'golf hole', broad appearance or lateral placement of ureteric orifices were classified as complex appearance ureters (CAU). Patients with persistent reflux were considered for second and third injections with the same material. Success was determined as no reflux.

RESULTS

The total success rate was 100, 92.30, 92, 80 and 66.66% for grade I, II, III, IV and V reflux after the third injection, respectively. The cure rates of ureters with normal appearance were 100, 88.88, 90, 100 and 100% for grade I, II, III, IV and V reflux. The cure rates of CAU were 100% for both grade II and III, 60% for grade IV and 50% for grade V reflux. The injected volumes per renal unit ranged between 0.2 and 3.2 ml (mean 1.05 ml).

CONCLUSIONS

Although there are disadvantages in the usage of higher volumes of injectable material for successful results and difficulty in subureteral injection both in high grade reflux and complex anatomical situations in adults when compared to children, our results indicate that endoscopic treatment of VUR is an effective therapy for adults.

Bladder ultrasound in the evaluation of the efficacy of dextranomer/hyaluronic acid injection for treatment of vesicoureteral reflux

PURPOSE

To determine whether sonographic examination of subureteral implants after endoscopic dextranomer/hyaluronic acid (DHA) injection would help to evaluate the efficacy of this method in the treatment of vesicoureteral reflux.

MATERIALS AND METHODS

Thirty-six patients (49 ureters) who underwent endoscopic subureteral DHA injection were evaluated using voiding cystourethrography (VCUG) and bladder sonography for a mean duration of 2.1 years (range, 3 months to 6.5 years) after treatment. Patient records-including the results of VCUG, renal sonography, Dimercapto succinic acid (DMSA) scintigraphy, and periodic urinary analysis-were also reviewed to determine the outcome of treatment.

RESULTS

Reflux was corrected in 43/49 (88%) ureters (complete cure in 38, downgrading of reflux in 5). No change was noted in 6 (12%) ureters on VCUG. The reflux was found to be corrected in 19/22 (86%) ureters, with the implants clearly identifiable on sonography. However, reflux was documented in only 3/27 (11%) ureters, around which no implant was seen on sonography.

CONCLUSION

The identification of the implant in the subureteral region by bladder sonography correlated with resolution of reflux in the early postinjection period. On the other hand, the majority of the implants disappeared on sonography in the long term despite correction of reflux. Therefore, we believe that the use of bladder sonography is not useful in the evaluation of patients in long-term follow-up.

Histological response to injected dextranomer-based implant in a rat model

To investigate the short and long term histopathological alterations caused by submucosal injection of dextranomers in sodium hyaluronan (DiHA) based on an experimental rat model. Sixty Sprague-Dawley rats were assigned into two groups as group I and II, each containing 30 rats. Totally 0.1 ml of saline solution and 0.1 ml of DiHA were injected into the submucosa of bladder of first (control) and second groups, respectively. Both group I and II were further subdivided into three other groups as Group IA, IB, IC and Group IIA, IIB, IIC according to the sacrificial period. Group IA and IIA, IB and IIB, IC and IIC rats (ten rats for each group) were sacrificed 3, 6, and 12 months after surgical procedure, respectively. Two slides prepared from injection site of the bladder were evaluated completely for each rat by being unaware of the groups and at random by two independent senior pathologists to determine the fibroblast invasion, collagen formation, capillary growth and inflammatory reaction. Additionally, randomized brain sections from each rat were also examined to detect migration of the injection material. The measurements were made using an ocular micrometer at 10x magnification. The results were assessed using t-tests for paired and independent samples, with P<0.05 considered to indicate significant differences; all values were presented as the mean (SD). Migration to the brain was not detected in any group. Significant histopathological changes in the DiHA injected groups were granuloma formation in 43.3%, foreign body type giant cells in 76.6%, inflammatory infiltration in 100%, and fibroblasts surrounding microspheres in 100% of the rat bladder. The interaction between granuloma formation and long-term tissue effects in children is still obscure. We emphasize that further prospective human (and/or animal) studies are required to clarify the long-term effects of granuloma formation with regard to clinical applications.

What are the most powerful determinants of endoscopic vesicoureteral reflux correction? Multivariate analysis of a single institution experience during 6 years

PURPOSE

As the indications for endoscopic correction of vesicoureteral reflux continue to expand, the emergence of potential predictive variables has been noted. We used univariate and multivariate statistical analyses to find the most significant predictors of correction to improve patient selection.

MATERIALS AND METHODS

A consecutive series of patients treated at a single institution was reviewed. Between August 1998 and August 2004, 232 children endoscopically injected with polydimethylsiloxane were identified, representing 351 refluxing units. A total of 23 variables were subjected to statistical analysis to detect predictors of reflux correction after injection. All identified patients with complete data and followup evaluations were included irrespective of anatomical variations, previous interventions or comorbidities.

RESULTS

The overall success rate by patient and renal unit was 65% and 72%, respectively. In patients with a single system low grade (1-3) vesicoureteral reflux who did not previously undergo injection this success rate increased to 80%. Univariate analysis demonstrated that higher physician experience, low preoperative vesicoureteral reflux grade, absent renal scars and no previous injections were statistically significant predictors of vesicoureteral reflux correction (p <0.05). A history of febrile urinary tract infections and a duplex system did not attain significance (p = 0.069 and 0.076, respectively). On multivariate statistical evaluation only physician experience, preoperative vesicoureteral reflux grade and the number of previous injections remained significant.

CONCLUSIONS

Multivariate analysis of our data showed the most important determinants of vesicoureteral reflux correction after endoscopic injection. Prospective validation will allow us to generate nomograms to better select and counsel patients who would benefit from vesicoureteral reflux treatment.

Histological response to injected gluteraldehyde cross-linked bovine collagen based implant in a rat model

BACKGROUND

The aim of present study is to investigate the short and long term histopathological alterations caused by submucosal injection of gluteraldehyde cross-linked bovine collagen based on an experimental rat model.

METHODS

Sixty Sprague-Dawley rats were assigned into two groups as group I and II each containing 30 rats. 0.1 ml of saline solution and 0.1 ml of gluteraldehyde cross-linked bovine collagen were injected into the submucosa of bladder of first (control) and second groups, respectively. Both group I and II were further subdivided into 3 other groups as Group IA, IB, IC and Group IIA, IIB, IIC according to the sacrification period. Group IA and IIA, IB and IIB, IC and IIC rats (10 rats for each group) were sacrificed 3, 6, and 12 months after surgical procedure, respectively. Two slides prepared from injection site of the bladder were evaluated completely for each rat by being unaware of the groups and at random by two independent senior pathologists to determine the fibroblast invasion, collagen formation, capillary ingrowth and inflammatory reaction. Additionally, randomized brain sections from each rat were also examined to detect migration of the injection material. The measurements were made using an ocular micrometer at x10 magnification. The results were assessed using t-tests for paired and independent samples, with p < 0.05 considered to indicate significant differences; all values were presented as the mean (SD).

RESULTS

Migration to the brain was not detected in any group. Significant histopathological changes in the gluteraldehyde cross-linked bovine collagen injected groups were fibroblast invasion in 93.3%, collagen formation in 73.3%, capillary ingrowth in 46.6%, inflamatory reaction in 20%.

CONCLUSION

We emphasize that the usage of gluteraldehyde cross-linked bovine collagen in children appears to be safe for endoscopic treatment of vesicoureteral reflux.

The effect of microsphere degradation rate on the efficacy of polymeric microspheres as bulking agents: An 18-month follow-up study

The injection of bulking substances has been proposed as a new therapy to treat urinary incontinence and vesicoureteral reflux. Our previous study demonstrated that poly(lactic-co-glycolic acid) (PLGA) microspheres have the potential to serve as a bulking agent for urological injection therapies. Hybrid tissues exhibiting a bulking effect were formed in vivo by PLGA microsphere injection, but long-term volume stability was not proven. In this study, we hypothesized that the biodegradation rate of the bulking substance (polymer microspheres) would affect the duration of volume conservation of the induced hybrid tissue. To test this hypothesis, rapidly degrading 75:25 PLGA microspheres and slowly degrading poly(L-lactic acid) (PLLA) microspheres were used as injectable bulking agents for the injection therapy. In vitro degradation tests showed that the mass losses of PLLA and PLGA were 16 and 96% of the initial masses, respectively, at 30 weeks. PLLA and PLGA microspheres were injected into the subcutaneous dorsum of mice. Both types of microspheres were easily injectable through 24-gauge needles. Histological examinations at various time points indicated that host cells from the surrounding tissues migrated to the spaces between both types of injected microspheres and formed new hybrid tissue structures. Lymphocyte migration was noted around the implanted PLGA and PLLA microspheres, but the inflammatory reaction diminished with time. Importantly, the volume of the PLLA hybrid tissues slowly decreased to 52% of the initial volume at 12 months and maintained that volume until 18 months, whereas the volume of the PLGA hybrid tissues rapidly decreased to 22% at 6 months, and the PLGA hybrid tissues disappeared at 11 months. These results show that the biodegradation rate of the bulking substance may be useful for controlling the duration of volume conservation of the induced hybrid tissue.

Complicaciones del tratamiento endoscópico del reflujo vesicoureteral en la infancia

INTRODUCTION

Nowadays, around 1% of children suffer from vesicoureteral reflux (VUR), which represents a risk factor for long-term kidney damage. In the last decade, development in this field has shown that subureteric endoscopic injection of bulking agents for childhood VUR is an acceptable alternative unlike long-term antibiotic prophylaxis and open surgery.

OBJECTIVE

To establish the complications of childhood VUR endoscopic treatment.

MATERIAL AND METHODS

A retrospective analysis was carried out for every patient treated endoscopically in our department from January 1999 to September 2003, with a total amount of 516 implants of submucous bulking agents. All patients were assessed with an ultrasound as a first diagnostic technique so as to establish the complications associated with it, especially ureteral obstruction and injected agent migration.

RESULTS

Out of 516 cases, Macroplastique was used in 455, Deflux in 44 and Polytef in 17. 10 patients (1.9%) (5 girls/ 5 boys), with ages ranging from 15 months to 11,4 years, presented some kind of complications (Macroplastique was used in 8cases and Deflux in 2). Among them, 5 were remarkable due to an ureterohydronefrosis, 2 of which needed a nephrostomy. 3 patients presented an implant migration, 1 epididymitis and 1 bladder edema.

CONCLUSIONS

Endoscopic bulking agent injection has become a safe alternative to open surgery in childhood VUR management.

Submucosal injection of poly(lactic-co-glycolic acid) microspheres in rabbit bladder as a potential treatment for urinary incontinence and vesicoureteral reflux: preliminary results

Endoscopic injection of bulking agents has been gaining attention as a therapy for urinary incontinence and vesicoureteral reflux because this therapy is simpler, less operation time-consuming and less painful than traditional surgical operations. The ideal bulking agent for the injection therapies must be easily injectable, biocompatible, volume-stable, non-antigenic and non-migratory. We evaluated poly(lactic-co-glycolic acid) (PLGA) microspheres as an injectable bulking agent for urologic injection therapies. To determine whether PLGA microspheres meet the requirements of an ideal bulking agent, PLGA microspheres were injected into the submucosal sites of a rabbit bladder wall. The microspheres were easily injectable. Two and five weeks post-implantation, histological examinations indicated that host cells from the surrounding bladder tissues migrated to the space between the injected microspheres and formed new hybrid tissue structures. Lymphocyte migration was noted around the implanted microspheres, but the inflammatory reaction diminished at 5 weeks. The hybrid tissue volume did not significantly decrease over time. There was no evidence of microsphere migration to the distant organs. Although long-term studies are needed to evaluate the therapeutic potential of this method, these preliminary results suggest the possibility of PLGA microspheres as a potentially useful injection material for urinary injection therapies.

Role of periureteral injections in children with vesicoureteral reflux

PURPOSE OF REVIEW

Periureteral injection has become an increasingly popular method for managing vesicoureteral reflux in children. This minimally invasive and seemingly effective technique, completed in a simple manner, is attracting more attention from urologists and parents alike. This review describes the contemporary experience with injection therapy and attempts to define its place in the algorithm for the management of vesicoureteral reflux.

RECENT FINDINGS

A variety of different substances have been tried as bulking agents to eliminate vesicoureteral reflux since the technique was introduced more than 20 years ago. Long-term follow-up has found drawbacks with each substance tried. Dextranomer polysaccharide microspheres crosslinked in sodium hyaluronan (Deflux; Ixion Biotechnology, Inc, Alachua, Florida, USA) have recently appeared as another alternative in treatment. Recent reports have focused on the efficacy of the material used in patients with different grades of reflux and in patients whose reflux is associated with other conditions. The substance has performed reasonably well in most initial studies but its cure rates do not approximate those of open surgery. Technical improvements and risk factors for failure are gradually being identified that are aimed at improving performance. The long-term efficacy of Deflux is not well defined and cost-analysis data of patients managed in a prospective randomized fashion are lacking.

SUMMARY

The role of periureteral injection therapy, for patients whose vesicoureteral reflux requires correction, remains unclear. Further studies are needed to elucidate its place in the algorithm for the management of this common problem in children.

[Subureteral polydimethylsiloxane injection for the endoscopic treatment of vesicoureteral reflux]

INTRODUCTION

Endoscopic subureteral injection has been successfully used to treat vesicoureteral reflux (VUR) in children. The aim of this study was to review our results with subureteral polydimethylsiloxane injection in terms of effectiveness, long term follow-up and morbidity.

MATERIAL AND METHOD

Twenty-eight children with VUR were treated with this technique. VUR was unilateral in eight patients (28.6%) and bilateral in 20 patients (71.4%). Indications for endoscopic treatment were the same as those for open surgery. The polydimethylsiloxane implant was injected transureterally below the ureteral meatus in 50 ureters on an outpatient basis. Reflux grade was low (II-III) in 36% and high (IV-V) in 64%.

RESULTS

The mean follow-up was 18 months (12 months-4 years). VUR was corrected in 43 ureters (86%) corresponding to 21 patients. Reflux resolved in 40 ureters after one polydimethylsiloxane injection (80%) and in 43 ureters (86%) after two injections. An endoscopic retreatment to correct the reflux was performed in six ureteral units. Cystoscopic findings in these patients with endoscopic failure were mound displacement toward the bladder neck in five ureters and marked volume loss on the mound in one. All these patients underwent a second subureteral dose, which controlled VUR in three ureters (50%).

CONCLUSIONS

Our results confirm that endoscopic subureteral polydimethylsiloxane treatment is a simple procedure with low morbidity that is well tolerated by the patient. In our experience, it can be used in double ureters. The effectiveness of this procedure seems to be related to the grade of reflux, the cystoscopic appearance of the ureteral orifice, volume loss and mound displacement.

[Primary vesicoureteral reflux treatment in childhood: comparsion of two systematic review]

Many medical practices are being carried out unawares of their efficiency, or of their actual impact on the health of the patients, therefore it is necessary to consider the support of professional recommendations with scientific evidence.

THE PRIMARY OBJECTIVE

To perform a systematic review (SR) of the therapeutic management of primary VUR in pediatric urology.

MATERIAL AND METHODS

A systematic review has been performed, including scientific evidence-based medicine criteria, of the articles published in all of the available databases. Inclusion criteria concerning basic quality of the articles were considered essential, as well as exclusion criteria to be able to reject the articles.

RESULTS AND DISCUSSION

Subsequently, and following the critic reading of greater than 320 articles, statistical study of the grouped data was performed according to the type of treatment and to the benefits contributed by each treatment, and also to their undesirable effects. Finally we have made a comparison between our results and recent Cochrane Systematic Review. The following Conclusions were drawn from the results obtained and from the analysis of the texts. Both medical and surgical treatment present with similar effectiveness concerning resolution of grades I, II and III of VUR, and the former one is the recommended initial treatment following diagnosis. Endoscopic treatment is exactly as effective as open surgery for grades I, II and III with fewer undesirable effects secondary. There are no differences concerning the efficacy of the different injected substances. Not enough evidences exist for degrees IV and V that may recommend or advise against any of the treatments. In any degree of VUR, open surgical treatment is superior as far as medical treatment is concerned only regarding the number of acute pyelonephritis episodes during followup. This conclusion cannot be applied on endoscopic treatment.

Endoscopic Treatment of Vesicoureteral Reflux with Polydimethylsiloxane in Adult Women

OBJECTIVES

Subureteral injection of bulking agents to a refluxing ureteral orifice is an attractive alternative to open repair. We record our experience of the endoscopic subureteral injection of polydimethylsiloxane in women for vesicoureteral reflux (VUR).

METHODS

From January 1997 to December 2001, 30 women (mean age 34.9 years) with 43 refluxing ureters underwent endoscopic treatment. The grade of VUR was I, II, III, and IV in 10, 16, 13, and 4 ureters, respectively. The indication for the procedure was VUR with a history of pyelonephritis in women of childbearing age or in whom antibiotic prophylaxis had been unsuccessful. All women underwent voiding cystourethrogram at 3 months and then yearly after the procedures. Follow-up ranged from 12 to 60 months (mean 26.5 months).

RESULTS

Reflux was corrected in 34 ureters after a single injection; only 3 ureters needed a 2nd injection. The overall success rate was 86.0%: for grades I, II, III, and IV was 90.0%, 87.5%, 76.9%, and 100% respectively. The mean hospital stay was 1.31 days (range 1-8 days), and no remarkable surgical complications occurred. Most of the patients in whom VUR was cured or improved showed a reduction in laboratory-proven urinary infection rates.

CONCLUSIONS

The endoscopic subureteral injection of polydimethylsiloxane in women with vesicoureteral reflux is an effective therapy with no associated morbidity.

Cystoscopic correction of reflux

Vesicoureteral reflux is a well-recognized cause of childhood illness and renal damage. In the past, surgical reimplantation had been the only procedure available to gain the immediate cessation of reflux. The development of an endoscopic injection technique as a less morbid alternative to traditional surgery began in the 1980s. Teflon was the first injectable agent to be investigated. The record of Teflon is one of efficacy and apparent patient tolerance. However, concerns regarding possible migration and other side effects led to a search for other injectable agents. The most recently investigated agents are polydimethylsiloxane and dextranomer polymer. These agents do not have the long-term follow-up of Teflon, but appear to be effective and safe. Time will tell which agent will become the implant of choice, but it seems clear that endoscopic management will play an increasingly larger role in the care of vesicoureteral reflux.

Poly(lactic-co-glycolic acid) microspheres as a potential bulking agent for urological injection therapy: Preliminary results

Injection of bulking substances has been introduced as a new therapy to treat urinary incontinence and vesicoureteral reflux. Currently available bulking substances for the injection therapies include liquid or particulated silicone, collagen gel, and polytetrafluoroethylene paste. However, these materials have shown shortcomings such as inflammation, rapid volume decrease, and particle migration to distant organs. In the present study, we evaluated poly(lactic-co-glycolic acid) (PLGA) microspheres as a potential injectable bulking agent for the injection therapies. PLGA microspheres (52 microm in average diameter) were injectable through various gauges of needles, as the injected microspheres showed no tendency to obstruct the needles and microsphere size exclusion was not observed upon injection through the needles. After injection of PLGA microspheres into the subcutaneous dorsum of mice, inflammation, new tissue volume change, and microsphere migration were examined. Host cells from the surrounding tissues migrated to the implanted microspheres and formed new hybrid tissue structures. The volume of the newly generated tissues was maintained approximately constant for 7 weeks. Histological analyses showed no evidence of migration of the implanted microspheres to the distant organs. In summary, PLGA microspheres were injectable and able to induce a new hybrid tissue formation without initial volume decrease or particle migration. These preliminary results suggest that this material may be a potentially useful bulking agent for urological injection therapies.

Mechanisms of failure of endoscopic treatment of vesicoureteral reflux based on endoscopic anatomy

PURPOSE

We examined the mechanisms responsible for technical failure of the endoscopic technique for correcting vesicoureteral reflux based on endoscopic anatomy.

MATERIALS AND METHODS

The study included 25 patients, 2 to 15 years old (mean age 8) who received 57 ureteral injections on 1 or more occasions which failed to correct reflux. Each endoscopic procedure for every patient was videotaped and endoscopic photographs were taken to document pretreatment and posttreatment anatomy. Based on the comparative endoscopic anatomical findings, failures were categorized as secondary to volume loss, mound displacement, mound extrusion or indeterminate etiology.

RESULTS

Of the 57 ureters the cause of failure was believed to be due to mound displacement in 35%, volume loss in 23%, displacement and volume loss in 29%, mound extrusion in 2% and indeterminate in 11%. The direction of mound displacement was toward the bladder neck (medial, distal) in 76% of those cases.

CONCLUSIONS

Endoscopic anatomical findings can account for failure of the injection technique to correct reflux in the majority of failed cases (90%). Mound displacement and volume loss account comparably for treatment failure. One incidence of mound extrusion, previously hypothesized as a mechanism for treatment failure, was documented in our study.

Polydimethylsiloxane Injection Versus Open Surgery for the Treatment of Vesicoureteral Reflux in Complete Duplex Systems

PURPOSE

We compared the efficacy of subureteral polydimethylsiloxane injection (Macroplastique, Uroplasty, Inc., Minneapolis, Minnesota) versus open surgery for correction of varying degrees of reflux in complete duplex systems.

MATERIALS AND METHODS

Between 1997 and 2000 polydimethylsiloxane injection was performed in 15 females (22 refluxing moieties). Mean patient age at presentation and at surgery was 54 and 94 months, respectively. Extravesical common sheath reimplantation (ECSR) was performed in 34 children (bilateral 10) with a mean age at presentation and at surgery of 31 and 57 months, respectively. Voiding cystourethrography and ultrasound were performed at 3 months. In cases of persistent reflux repeat voiding cystourethrography was performed at followup. We then analyzed the surgical outcome for both groups.

RESULTS

Mean followup for the injection and ECSR groups was 12 and 15 months, respectively. The success rate per moiety after injection was 68% at 3 months, which increased to 81.8% at 12 months. One patient had contralateral vesicoureteral reflux and none had de novo hydronephrosis, urinary tract infection or complications postoperatively. The success rate of ECSR was 95.5% at 3 months, which improved to 97.7% at an average of 15 months (p <0.04). After ECSR transient contralateral vesicoureteral reflux was seen in 4 renal units, de novo hydronephrosis was seen in 2 units and 4 patients had urinary tract infections.

CONCLUSIONS

Although endoscopic subureteral polydimethylsiloxane injection was simple and successful in more than 80% of patients with low grade vesicoureteral reflux in duplex systems, it is less effective than surgery with regard to elimination of reflux.

Treatment of Vesicoureteral Reflux by Endoscopic Injection of Dextranomer/Hyaluronic Acid Copolymer: Preliminary Results

PURPOSE

Endoscopic subureteral injection of tissue augmenting substances has become an established alternative to long-term antibiotic prophylaxis and open surgery for the management of vesicoureteral reflux (VUR) in children. Recently, dextranomer/hyaluronic acid copolymer (Deflux, Q-Med AB, Uppsala, Sweden) a biodegradable injectable material has been reported to be a promising alternative to other tissue augmenting substances. However, the experience with dextranomer/hyaluronic acid copolymer is limited. We prospectively evaluate the effectiveness of dextranomer/hyaluronic acid copolymer in the endoscopic treatment of VUR.

MATERIALS AND METHODS

A total of 32 males and 81 females with a median age of 1 year (range 3 months to 10 years) underwent endoscopic correction of primary VUR with dextranomer/hyaluronic acid copolymer. Reflux was unilateral in 58 cases and bilateral in 54, affecting 166 ureters. Reflux was grades II to V in 7 (4.2%) cases, 91 (54.8%), 63 (38%) and 5 (3%), respectively. All patients underwent endoscopic correction as a day procedure and have been followed for 3 months to 1 year.

RESULTS

The reflux was corrected in 143 (86%) of the 166 ureters after a single injection, and resolved after a second and third injection in 22 (13%) and 1 (1%) ureter, respectively. No untoward effects were seen in any of these patients with the use of dextranomer/hyaluronic acid copolymer as an injectable material.

CONCLUSIONS

Dextranomer/hyaluronic acid copolymer is an effective tissue augmenting substance in the endoscopic treatment of all grades of VUR.

Endoscopic treatment of primary grades IV and V vesicoureteral reflux in children with subureteral injection of polytetrafluoroethylene

PURPOSE

We evaluated our experience with endoscopic STING (subureteral polytetrafluoroethylene injection) for grades IV and V vesicoureteral reflux.

MATERIALS AND METHODS

We reviewed the records of 221 boys and 305 girls who underwent STING for primary grades IV (430) and V (96) vesicoureteral reflux between 1984 and 2000. Median patient age at STING was 3 years (range 3 months to 14 years). Reflux was unilateral and bilateral in 335 and 191 children, respectively (717 refluxing units). Median followup was 11.6 years (range 1 to 17).

RESULTS

Reflux was corrected in 420 of the 717 refluxing units (58%) after a single injection. Reflux resolved after a second and third injection in 185 ureters (26%). High grade reflux was converted to grades I and II in 112 ureters (15%) and did not require any further treatment. STING failed to correct reflux in 7 units (0.9%), which were managed by ureteral reimplantation (5) and nephrectomy (2) due to poor renal function. Voiding cystourethrography showed recurrent vesicoureteral reflux in 9 units (1.2%), including 2 with low grade reflux for which no treatment was given. Seven ureters required repeat injection due to grades III and IV reflux. No untoward effects were noted in any patients in whom polytetrafluoroethylene was used as the injected material.

CONCLUSIONS

STING is a simple, safe and effective outpatient procedure for grades IV and V vesicoureteral reflux.

Subureteral polydimethylsiloxane injection versus extravesical reimplantation for primary low grade vesicoureteral reflux in children: a comparative study

PURPOSE

We compare the outcome of extravesical ureteral reimplantation to endoscopic polydimethylsiloxane (Macroplastique, Uroplasty, Inc., Minneapolis, Minnesota) subureteral injection for primary low grade vesicoureteral reflux in children.

MATERIALS AND METHODS

Between 1997 and 2000, 180 patients underwent polydimethylsiloxane injection (74, 108 ureters) or extravesical ureteral reimplantation (106, 166 ureters) for low grade vesicoureteral reflux. Low grade reflux was defined as grades I to III. Outcome analysis included success rates, de novo hydronephrosis, voiding efficiency, urinary tract infections and complications.

RESULTS

Mean patient age at surgery for the injection and surgery groups was 60 and 77 months, and mean followup was 12 and 15 months, respectively. Of the patients who underwent single injection 80.6% were cured of reflux at 3 months and 91.6% were cured at last followup. Success rate after reimplantation was 95.8% at 3 months which improved to 98.8% 1 year later. The success rate was significantly different between the injection and reimplantation groups at 3 and 12 months (p <0.01). Postoperative complications in the reimplantation group included transient urinary retention after bilateral surgery in 2 patients (3.3%), suprapubic fluid collections in 2 and wound seroma in 1. No complications occurred in the polydimethylsiloxane group.

CONCLUSIONS

Extravesical ureteral reimplantation has near perfect success with a low but definite complication rate. Polydimethylsiloxane offers high success rates for reflux in an ambulatory setting with no short-term complications. Currently, endoscopic polydimethylsiloxane injection is our preferred mode of therapy for low grade vesicoureteral reflux in children when surgical correction is indicated.

Outcome of endoscopic treatment for vesicoureteral reflux in children using polydimethylsiloxane

PURPOSE

We reviewed the outcome of subureteral injection of polydimethylsiloxane as a bulking agent for endoscopic treatment for vesicoureteral reflux in patients younger than 12 years.

MATERIALS AND METHODS

A total of 40 children (59 ureters) with primary grades II to IV vesicoureteral reflux were treated with a single subureteral injection from 1997 to 2001 and followed an average of 26 months (range 4 to 45). Results in 38 patients (55 ureteral units) were available for review. Each child underwent preoperative voiding cystourethrography, renal ultrasound, dimercapto-succinic acid scan and urine culture. Treatment was done on an outpatient basis. With the patient general anesthesia polydimethylsiloxane implant was injected transurethrally below the ureteral opening of the affected renal unit. Renal ultrasound at 1 week and voiding cystourethrography at 2 months were done to rule out obstruction at the injection site and/or persistent reflux, respectively. Cure was defined as absent vesicoureteral reflux on voiding cystourethrography 2 months after injection.

RESULTS

After a single injection polydimethylsiloxane cured vesicoureteral reflux in 45 ureteral units (81.8%), while in 5 (9.1%) the condition was improved. The remaining 5 ureteral units (9.1%) showed no change in reflux grade. In 1 patient (1.9%) with unilateral grade IV vesicoureteral reflux contralateral reflux developed. None of the cured patients had recurrent reflux during followup. In 1 patient ureteral obstruction was successfully treated with ureteral reimplantation.

CONCLUSIONS

Endoscopic subureteral injection of polydimethylsiloxane implant in children with primary grades II to IV vesicoureteral reflux appears to be an effective, safe and minimally invasive technique.

Prospective comparison and 1-year follow-up of a single endoscopic subureteral polydimethylsiloxane versus dextranomer/hyaluronic acid copolymer injection for treatment of vesicoureteral reflux in children

OBJECTIVES

To compare, in a prospective study, the efficacy of a single injection of polydimethylsiloxane (Macroplastique) or dextranomer/hyaluronic acid copolymer (Deflux), a new biodegradable substance, and to assess the short-term and 1-year clinical effects concerning reflux resolution and the safety of these two bulking agents. Subureteral injection of bulking agents has recently demonstrated good success rates for endoscopic treatment of vesicoureteral reflux. Macroplastique has been one of the most popular bulking agents during the past years. Nevertheless, considering the synthetic property, new biodegradable substances have become more relevant.

METHODS

From January 2000 to June 2001, 16 boys and 56 girls (total of 114 ureters) with a mean age of 34.5 months were treated endoscopically for vesicoureteral reflux. A single subureteral Macroplastique or Deflux injection was performed in 34 children (58 ureters) and 38 children (56 ureters), respectively. Both groups were comparable in terms of baseline parameters. Vesicoureteral reflux was grade II in 52, grade III in 57, and grade IV in 5 ureterorenal units. The procedure was performed on an outpatient basis, with the children under general anesthesia. In addition to the routine parameters, the follow-up evaluation consisted of renal ultrasonography and voiding cystourethrography at 3 and 12 months postoperatively.

RESULTS

Endoscopic treatment was performed without any complications in all cases. At the 3-month follow-up visit, reflux was corrected in 50 (86.2%) of 58 refluxing ureters in the Macroplastique group and in 40 (71.4%) of 56 refluxing ureters in the Deflux group. At 1 year of follow-up, reflux correction was maintained in 80.9% of ureters in the Macroplastique group and in 67.6% of ureters in the Deflux group. No postoperative complications were observed in either group.

CONCLUSIONS

A single subureteral injection of either polydimethylsiloxane (Macroplastique) or dextranomer/hyaluronic acid copolymer (Deflux) is an effective treatment modality for children with vesicoureteral reflux. The procedure was well tolerated, safe, and associated with low morbidity. Deflux, a new biocompatible, biodegradable substance, seems to be an alternative modality to other bulking agents for treating vesicoureteral reflux in children, with acceptable short-term and 1-year results.

Review of the available urethral bulking agents

PURPOSE OF REVIEW

Newer tissue bulking agents used to treat stress urinary incontinence and vesicoureteral reflux provide for similar rates of success as older agents, but with greater safety and hopefully with greater durability. We review the new studies on the development and on the current trials of bulking agents.

RECENT FINDINGS

Recent reports suggest that periurethral bulking agents are as effective for genuine stress urinary continence as for intrinsic sphincter deficiency, expanding the indications for injectable agents to include patients desiring less invasive procedures due to personal preference or as a result of medical necessity. Newer bulking agents, Durasphere and Macroplastique, appear safe and as efficacious as older agents in early trials. Durability remains a question for these agents. Injectable tissue matrices and autologous cells may prove useful in the future.

SUMMARY

If durable and safe, these minimally invasive bulking agents may prove useful for all types of stress urinary incontinence. The price of minimal invasiveness may be lower efficacy, but their use does not compromise further therapy, should it be needed.